1. Field of the Invention
The present invention relates to a digital television system, and more particularly, to a synchronization signal detector and related method of the digital television system.
2. Description of the Prior Art
Due to the need for decoding a digital TV signal, the digital TV signal is designed to contain a fixed pattern, which appears repeatedly, to allow a digital TV receiver to synchronize the digital TV signal accordingly. Taking a digital TV signal used in the U.S.A. as an example, the digital TV signal complies with a specification defined by an Advanced Television Systems Committee (ATSC). According to the specification, each data field contains 313 segments, and the beginning of each segment corresponds to a four-symbol fixed pattern which is commonly called segment SYNC or data segment SYNC. For convenience, these four symbols will hereafter be called sync symbols.
The synchronization of the digital TV signal is achieved by identifying the sync symbol in the received digital TV signal through the aid of a reference signal containing the same sync symbol. Because of the interference caused by the noise or transmission path variations, however, the sync symbol in the received signal may in actuality differ from the sync pattern in the reference signal, which causes synchronization errors to occur due to the failure of identifying the sync symbol in the digital TV signal.